Tools update issue

followed the ISPConfig First Step tutorial.
Tools/Plugin using URL method returns error.
However I could separately go to ISPConfig site to download e.g. roundcube, phpmyadmin and then use ISPConfig-tool to install using File instead of URL.
1. Is there some module missing in my ISPConfig?
2. Will subsequent versionsn of e.g roundcune be updated automatically using File method?
3. How to remove e.g roundcube?

Can access Phpmyadmin ok. Supplying the same userid/pword for roundcube, nogo...closed the browser, didnt have patience to wait for > 1 minute.
4, Whats wrong ?